1. Field of the Invention
This invention relates generally to fluid pressure oscillators of the type employed to reciprocate various mechanical devices, and is concerned in particular to an improved arrangement for controlling the operation of such oscillators.
2. Description of the Prior Art
A typical fluid pressure oscillator is disclosed in U.S. Pat. No. 2,987,051 (Goyette et al). Here, the reciprocating movement of the piston assembly is controlled by a relatively complicated valve assembly located inside the cylinder. In order to gain access to the valve assembly when performing repair and/or routine maintenance, the actuator must be almost entirely dismantled and thereafter reassembled.
Such procedures are extremely time consuming, and difficult to perform satisfactorily while the oscillators remain mounted in their "on line" operative position on production machinery. Consequently, when repairs or maintenance are required, the oscillators are normally entirely replaced by spare oscillators that are either new or that have been subjected to "off line" repairs and/or reconditioning. Oscillators are relatively expensive components and therefore the need to maintain an inventory of spares significantly increases overall production costs.